US2283461A - Kerf-cutting machine - Google Patents
Kerf-cutting machine Download PDFInfo
- Publication number
- US2283461A US2283461A US361030A US36103040A US2283461A US 2283461 A US2283461 A US 2283461A US 361030 A US361030 A US 361030A US 36103040 A US36103040 A US 36103040A US 2283461 A US2283461 A US 2283461A
- Authority
- US
- United States
- Prior art keywords
- shaft
- machine
- frame
- mine
- turntable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000005065 mining Methods 0.000 description 7
- 238000004873 anchoring Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C35/00—Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
- E21C35/06—Equipment for positioning the whole machine in relation to its sub-structure
Definitions
- This invention relates to improvements in kericutting machines adapted to cut a horizontal kerf in the mine wall along the roof or at various intermediate positions between the roof and floor.
- One of the principal objects of the invention is to combine the relatively high cutting capacity of heavy-duty kerf-cutting machines of the ⁇ type heretofore mounted on wheeled trucks and operated on the mine track, with the decreased height and greater flexibility of movement attained by room and pillar and longwall machines, which are slidable along the mine floor by means of cables.
- Other' objects of the invention will appear from the following description.
- Figure 2 is a side View of the machine shown in Figure 1, with parts broken 'away to show certain gearing details;
- Figure 3 is a detail section taken on line 3-3 of Figure l;
- FIG. 4 is a detail section taken on line 4-4 of Figure 1;
- Figures 5 and 6 are enlarged detail sections taken on lines 5-5 and 5 6, respectively, of Figure 1.
- I indicates generally a skid adapted to slide universally over the mine floor, and forming the base frame and main support for the machine.
- Said skid is in the form of a flat plate Il having marginal side "iianges I2, I2, rear flange I3, and front flange I4.
- a relatively wide turntable I is rotatably mounted close to the top of the skid plate I I, the adjacent portions of the side and front marginal flanges of the latter being cut away to Aaccommodate the projecting edges of said turntable.
- the rotatable mounting for the turntable comprises a at annular bearing Il fixed to the bottom plate Il, supporting an annular bearing ring I8 formed on the bottom of the turntable I5 and secured to the latter by a detachable outer ring I9, as shown in Figure 3.
- a cutting mechanism supporting means indicated generally at 20, affording vertical adjustment and transverse tilting for a cutter bar 25.
- the supporting means shown herein is in the main similar to that shown in my U. S. Patent No. 2,102,743, issued on Dec. 21, 1937, and includes as its principal elements a pair of vertically extending guide frame members 22, 22, between which is mounted a vertically adjustable cradle 23 having a-frame 24 trunnioned therein for ⁇ tilting on a transverse axis.
- the frame 24 forms a support for the rear end of the cutter bar 25, and carries a motor 25 operatively connected with a cutter chain 2l of said cutter bar, and also having gearing driven thereby for adjusting the cradle 23 vertically relative to said guide frame members.
- the frame 24 is provided with a pair of oppositely disposed bored bosses 23 extending laterally therefrom intermediate the ends of said frame.
- Each of said bosses has a bored trunnion support member 29 mounted therein and extending laterally therefrom.
- Each of said trunnion support members is journaled in a side frame member 30 of the cradle 23 in such ia manner that the entire frame 24 with its cutter bar may be tilted about the transverse axis defined by said trunnion supports.
- the side frames 30 of the cradle 23 extend along the frame 24 and are guided for vertical movement between the vertical guide frame members 22.
- Each of said guide frame members has a pair of vertically disposed racks 32 at opposite ends thereof, said racks being meshed with pinions 33, 33 on the opposite ends of longitudinally extending shafts 34, 34 rotatably supported at opposite ends of said side frames 30.
- Each shaft has a Worm gear 35 keyed thereto and disposed in a housing 36 formed integral with its respective side frame, the upper portion of which housing also forms the bearing support for the adjacent trunnion support member 28.
- Said worm gears are meshed with worms 31, 3l on the opposite ends of a transversely extending shaft 39, which extends coaxially through the trunnion support members 29, 29.
- the transverse shaft'39 has a helical gear 4i) thereon, driven by a helical pinion 4I on a stub shaft 42 disposed longitudinally of the frame 24 adjacent the central portion thereof, as shown in Figures 1 and 3.
- a main .shaft 45 extends longitudinally forward from the motor 26 and is connected thereto by a' gear 4B meshing with a motor pinion 4l.
- the ⁇ helical pinion 4I andY shaft 42 are selectively driven by said main shaft -in reverse directions through a reversing gear mechanism of any well known form, such as that disclosed in my Patent No. 2,102,743, and including opposed sliding clutch members 48 and 49 on the main shaft adapted to drive the sleeve 42 either through gears 5
- the cradle 23 and frame 24 may be adjusted vertically relative to the guide frame members 22, 22, and will be held in fixed relation with respect thereto by means of the worms and .worm gears, 31 and 35, which are of the usual selflocking type.
- the main shaft 45 also drives the cutter chain 21 about the cutter bar 25 through a suitable gear train, herein including a bevel pinion 55, bevel gear 56, sprocket shaft 51 and sprocket 53, all carried at the forward end of the frame 24.
- a suitable gear train herein including a bevel pinion 55, bevel gear 56, sprocket shaft 51 and sprocket 53, all carried at the forward end of the frame 24.
- Means are provided for tilting the frame 24 and the cutter bar about the trunnion supports, as herein shown such means including an outboard support 59 including arms 6
- a worm gear 64 is mounted in the housing 52 on a vertical axis, and is driven by a worm 66 on transverse shaft 61, journaled in said housing.
- An upright screw shaft 58 is threaded in the worm gear 64 and extends upwardly into pivotal connection at 65 with the forward end of the tilting frame 25 beneath cutter bar 25, as vis clearly shown in Figures 2 and 3.
- v shaft 61 extend freely through the arms 5
- a pair of cable drums 19, 19 are mounted at opposite sides of the base frame or skid i9, as herein shown said drums being rotatably mounted on a transverse shaft 1
- Said drums are of similar form and arrangement to those Vheretofore used in shortwall mining machines, being provided vwith cables 12, 12 which may be selectively trained about sheaves 13, 13, supported by Vprojecting brackets 13a, 13a at the front corners,
- the drums 19 are each arranged to be connected for rotation from the cross-shaft 1l by an ordinary pin clutch 15 carried by web 16 of the drum, and adapted to be detachably engaged with a hub'member 11 keyed tothe shaft 1
- Each drum also has a friction band 18 associated therewith, arranged to retardrotation thereof in the usual manner when its respective cable is to be payed out under frictional resistance.
- the drums 10 are driven from a motor 30 mounted adjacent the rear of bed plate and connected to the cross shaft 1
- is of a familiar type for providing two driving speeds under frictional control o'f friction bands 83 and 84, as heretofore employed in flexible feed drives for mining machines, so details of such planetary device need not be described herein.
- a driven shaft 35 of said planetary has a bevel pinion 86 of the reversing mechanism 82 which is also of a well known form, including bevel gears 81, 88 loosely mounted on shaft 1
- can be driven in reverse directions at a plurality of frictionally controlled speeds.
- the turntable I5 is also swung by power of the motor 89 for feeding the cutter bar arcuately across the front of the machine.
- a worm 99 is loosely mounted on the cross shaft 1
- a worm gear 92 is rotatably mounted on a vertical shaft 93 in housing 99.
- a chain sprocket 95 is mounted on the lower end of shaft 93 and has a chain 95 trained thereabout which extends .around the turntable I5. Since the cross shaft 1
- This chain drive for the turntable provides not only a simple and effective swinging mechanism, but assists in keeping the height of the machine to a minimum.
- screw jack 99 is mounted on a projecting bracket
- Each of said screw jacks consists of an upright screw
- Fixed to the upper end of each screw is a suitable head
- Said mine jack may be of the usual telescopic form including .a hand adjusting ring
- a jack of this kind is detachably .mounted between the mine roof and the head
- the screw jacks 91, v98 or 99 . can be rotated for tilting the machine base plate relative to the floor while they are anchored in place by the mine jacks H9.
- Said screw jacks can also be employed for tilting the machine when the mine jacks are not in use.
- the advantages of the mining machine above described will now be understood as follows:
- the skid mounting affords a machine of low height so that the machine can be used under lower roof conditions than is possible with track mounted cutting machines.
- the machine can be moved in any direction along the mineoor so as to be placed at the lmost advantageous positions relative to the working face. Under most conditions the machine is designed to cut by swinging the turntable while the base frame is anchored in place, but under some conditions the machine can be maneuvered for'cutting by means of the cables,
- the screw jacks 91, 98 and 99 can be used to tilt the machine, Whenever necessary, for guiding the cutter bar at a desired angle relative to the working face.
- a base frame including a skid adapted for slidable supporting en* gagement with the mine iioor, a turntable mounted on said base frame to swing on a vert cal axis, cutting mechanism including a chain carrying cutter bar mounted on said turntable, iiexible draft means on said base frame for moving the latter along the mine fioor, and a plurality of horizontally spaced supporting brackets rigid with said base frame, each having an upright screw member threaded therein and each of said screw members having a shoe at its lower end adapted for slidable supporting engagement with the ground, ⁇ and each of said screw members also having a mine jack detachably and rotatably engageable with the upper end thereof for anchoring said shoe relative to the ground, so as to provide tilting adjustment of said base fra/me and turntable as a whole relative to the mine oor, either While the machine is being moved along the mine oor or is ⁇ anchored relative thereto.
- a base frame including a skid in slidable supporting engagement with the mine floor, a turntable mounted at the front of said base fram-e to swing on a vertical axis,
- cutting mechanism including a chain carrying THOMAS E. PRAY.
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Drilling And Exploitation, And Mining Machines And Methods (AREA)
Description
T. E'. PRAY KERF-GUTTING MACHINE May 19, 1942.
2 Sheets-Sheet 1 Filed OCt. 14, 1940 T. E. PRAY KERF- May 19, 1942.
CUTTING MACHINE 2 Sheets-Sheet 2 Filed oct. 14, 1,940
.PLQ ATTORNEY m-UW INVENTOR ofzgfEP/l@ @QM/12 Patented May 19, 1942 REEF-CUTTING MACHINE Thomas E. Pray, Chicago, Ill., assignor to Good- .man Manufacturing Company, Chicago, Ill., a
corporation of Illinois Application October 14, 1940, Serial No. 361,030
2 Claims.
This invention relates to improvements in kericutting machines adapted to cut a horizontal kerf in the mine wall along the roof or at various intermediate positions between the roof and floor.
One of the principal objects of the invention is to combine the relatively high cutting capacity of heavy-duty kerf-cutting machines of the `type heretofore mounted on wheeled trucks and operated on the mine track, with the decreased height and greater flexibility of movement attained by room and pillar and longwall machines, which are slidable along the mine floor by means of cables. Other' objects of the invention will appear from the following description.
The invention may best be funderstood by reference to the accompanying drawings Where- Figure l is a fragmentary plan view of a mining machine constructed in accordance with, my invention, and with parts broken away to show certain gearing details;
Figure 2 is a side View of the machine shown in Figure 1, with parts broken 'away to show certain gearing details;
Figure 3 is a detail section taken on line 3-3 of Figure l;
Figure 4 is a detail section taken on line 4-4 of Figure 1;
Figures 5 and 6 are enlarged detail sections taken on lines 5-5 and 5 6, respectively, of Figure 1.
Referring now to details of the embodiment of my invention illustrated in the drawings, I indicates generally a skid adapted to slide universally over the mine floor, and forming the base frame and main support for the machine. Said skid is in the form of a flat plate Il having marginal side "iianges I2, I2, rear flange I3, and front flange I4.
A relatively wide turntable I is rotatably mounted close to the top of the skid plate I I, the adjacent portions of the side and front marginal flanges of the latter being cut away to Aaccommodate the projecting edges of said turntable. In the form shown herein, the rotatable mounting for the turntable comprises a at annular bearing Il fixed to the bottom plate Il, supporting an annular bearing ring I8 formed on the bottom of the turntable I5 and secured to the latter by a detachable outer ring I9, as shown in Figure 3.
Mounted on the turntable is a cutting mechanism supporting means indicated generally at 20, affording vertical adjustment and transverse tilting for a cutter bar 25. The supporting means shown herein is in the main similar to that shown in my U. S. Patent No. 2,102,743, issued on Dec. 21, 1937, and includes as its principal elements a pair of vertically extending guide frame members 22, 22, between which is mounted a vertically adjustable cradle 23 having a-frame 24 trunnioned therein for` tilting on a transverse axis. The frame 24 forms a support for the rear end of the cutter bar 25, and carries a motor 25 operatively connected with a cutter chain 2l of said cutter bar, and also having gearing driven thereby for adjusting the cradle 23 vertically relative to said guide frame members.
The frame 24 is provided with a pair of oppositely disposed bored bosses 23 extending laterally therefrom intermediate the ends of said frame. Each of said bosses has a bored trunnion support member 29 mounted therein and extending laterally therefrom. Each of said trunnion support members is journaled in a side frame member 30 of the cradle 23 in such ia manner that the entire frame 24 with its cutter bar may be tilted about the transverse axis defined by said trunnion supports.
The side frames 30 of the cradle 23 extend along the frame 24 and are guided for vertical movement between the vertical guide frame members 22.' Each of said guide frame members has a pair of vertically disposed racks 32 at opposite ends thereof, said racks being meshed with pinions 33, 33 on the opposite ends of longitudinally extending shafts 34, 34 rotatably supported at opposite ends of said side frames 30. Each shaft has a Worm gear 35 keyed thereto and disposed in a housing 36 formed integral with its respective side frame, the upper portion of which housing also forms the bearing support for the adjacent trunnion support member 28. Said worm gears are meshed with worms 31, 3l on the opposite ends of a transversely extending shaft 39, which extends coaxially through the trunnion support members 29, 29.
The transverse shaft'39 has a helical gear 4i) thereon, driven by a helical pinion 4I on a stub shaft 42 disposed longitudinally of the frame 24 adjacent the central portion thereof, as shown in Figures 1 and 3. A main .shaft 45 extends longitudinally forward from the motor 26 and is connected thereto by a' gear 4B meshing with a motor pinion 4l. The` helical pinion 4I andY shaft 42 are selectively driven by said main shaft -in reverse directions through a reversing gear mechanism of any well known form, such as that disclosed in my Patent No. 2,102,743, and including opposed sliding clutch members 48 and 49 on the main shaft adapted to drive the sleeve 42 either through gears 5|) and 5| or gears 52, 53 and 54.
The cradle 23 and frame 24 may be adjusted vertically relative to the guide frame members 22, 22, and will be held in fixed relation with respect thereto by means of the worms and .worm gears, 31 and 35, which are of the usual selflocking type.
The main shaft 45 also drives the cutter chain 21 about the cutter bar 25 through a suitable gear train, herein including a bevel pinion 55, bevel gear 56, sprocket shaft 51 and sprocket 53, all carried at the forward end of the frame 24.
Means are provided for tilting the frame 24 and the cutter bar about the trunnion supports, as herein shown such means including an outboard support 59 including arms 6|, 6| extending forwardly from the side frame members 30 of cradle 23 and having a gear housing 62 trunnioned in the forward end thereof at 53, 63. A worm gear 64 is mounted in the housing 52 on a vertical axis, and is driven by a worm 66 on transverse shaft 61, journaled in said housing. An upright screw shaft 58 is threaded in the worm gear 64 and extends upwardly into pivotal connection at 65 with the forward end of the tilting frame 25 beneath cutter bar 25, as vis clearly shown in Figures 2 and 3. The opposite ends ofv shaft 61 extend freely through the arms 5|, 5| of the outboard support 90, and have hand wheels 59, 59 thereon, to permit tilting adjustment of the frame 29 and cutter bar 25 relative to the cradle 23, from either side of the machine.
Referring now to the mechanism for transporting the machine about the mine and for moving it into cutting position, a pair of cable drums 19, 19 are mounted at opposite sides of the base frame or skid i9, as herein shown said drums being rotatably mounted on a transverse shaft 1| extending from one side of the machine to the other, and journaled in the upright side iianges |2, |2 of the base frame. Said drums are of similar form and arrangement to those Vheretofore used in shortwall mining machines, being provided vwith cables 12, 12 which may be selectively trained about sheaves 13, 13, supported by Vprojecting brackets 13a, 13a at the front corners,
and by sheaves 14, 14 supported by projecting brackets Ma, 14a at the-rear corners of the main frame I3. The cables 12, 12 can be trained over said sheaves so as to maneuver the machine as a whole universally over the mine floor, in the usual manner, by anchoring the ends of said cables in any desired direction and drawing in said cables by power or` paying them out under frictionally controlled resistance. In the form shown herein, the drums 19 are each arranged to be connected for rotation from the cross-shaft 1l by an ordinary pin clutch 15 carried by web 16 of the drum, and adapted to be detachably engaged with a hub'member 11 keyed tothe shaft 1|. Each drum also has a friction band 18 associated therewith, arranged to retardrotation thereof in the usual manner when its respective cable is to be payed out under frictional resistance.
The drums 10 are driven from a motor 30 mounted adjacent the rear of bed plate and connected to the cross shaft 1| through a planetary gear reduction device indicated generally at 8l and a reversing clutch mechanism indicated generally at 82.
The planetary gear reduction device 8| is of a familiar type for providing two driving speeds under frictional control o'f friction bands 83 and 84, as heretofore employed in flexible feed drives for mining machines, so details of such planetary device need not be described herein. A driven shaft 35 of said planetary has a bevel pinion 86 of the reversing mechanism 82 which is also of a well known form, including bevel gears 81, 88 loosely mounted on shaft 1| and selectively connected thereto by a sliding clutch member 89 feathered on said shaft between said bevel gears.
By the gearing arrangement just described, thecross shaft 1| can be driven in reverse directions at a plurality of frictionally controlled speeds.
The turntable I5 is also swung by power of the motor 89 for feeding the cutter bar arcuately across the front of the machine. For this purpose, a worm 99 is loosely mounted on the cross shaft 1|, and is selectively connected thereto by sliding clutch member 9|. A worm gear 92 is rotatably mounted on a vertical shaft 93 in housing 99. A chain sprocket 95 is mounted on the lower end of shaft 93 and has a chain 95 trained thereabout which extends .around the turntable I5. Since the cross shaft 1| can be reversely driven at a plurality of speeds, as previously described, the turntable can be swung in either direction by proper manipulation Yof clutch 9|, reversing mechanism`82, and planetary 8|. This chain drive for the turntable provides not only a simple and effective swinging mechanism, but assists in keeping the height of the machine to a minimum.
The advantages of the mining machine above described will now be understood as follows: The skid mounting affords a machine of low height so that the machine can be used under lower roof conditions than is possible with track mounted cutting machines. The machine can be moved in any direction along the mineoor so as to be placed at the lmost advantageous positions relative to the working face. Under most conditions the machine is designed to cut by swinging the turntable while the base frame is anchored in place, but under some conditions the machine can be maneuvered for'cutting by means of the cables,
in a manner similar to room and pillar or longwall mining machines. In either case, however, the screw jacks 91, 98 and 99 can be used to tilt the machine, Whenever necessary, for guiding the cutter bar at a desired angle relative to the working face.
While I have herein shown and described one form in which my invention may be embodied, it will be understood that the construction thereof and the arrangement of the various parts may be altered Without departing from the spirit and scope thereof. Furthermore, I do not Wish to b-e construed as limiting my invention to the speciiic embodiment illustrated, excepting as it may be limited in the appended claims.
I claim as my invention:
1. In a mining machine, a base frame including a skid adapted for slidable supporting en* gagement with the mine iioor, a turntable mounted on said base frame to swing on a vert cal axis, cutting mechanism including a chain carrying cutter bar mounted on said turntable, iiexible draft means on said base frame for moving the latter along the mine fioor, and a plurality of horizontally spaced supporting brackets rigid with said base frame, each having an upright screw member threaded therein and each of said screw members having a shoe at its lower end adapted for slidable supporting engagement with the ground,`and each of said screw members also having a mine jack detachably and rotatably engageable with the upper end thereof for anchoring said shoe relative to the ground, so as to provide tilting adjustment of said base fra/me and turntable as a whole relative to the mine oor, either While the machine is being moved along the mine oor or is `anchored relative thereto.
2. In a mining machine, a base frame including a skid in slidable supporting engagement with the mine floor, a turntable mounted at the front of said base fram-e to swing on a vertical axis,
cutting mechanism including a chain carrying THOMAS E. PRAY.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US361030A US2283461A (en) | 1940-10-14 | 1940-10-14 | Kerf-cutting machine |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US361030A US2283461A (en) | 1940-10-14 | 1940-10-14 | Kerf-cutting machine |
Publications (1)
Publication Number | Publication Date |
---|---|
US2283461A true US2283461A (en) | 1942-05-19 |
Family
ID=23420364
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US361030A Expired - Lifetime US2283461A (en) | 1940-10-14 | 1940-10-14 | Kerf-cutting machine |
Country Status (1)
Country | Link |
---|---|
US (1) | US2283461A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2650811A (en) * | 1947-06-17 | 1953-09-01 | Joy Mfg Co | Tilting arrangement for shortwall coal cutting machines |
US2678204A (en) * | 1950-07-17 | 1954-05-11 | Joy Mfg Co | Tiltable mounting structure for coal cutting machines |
US8789892B2 (en) | 2010-10-29 | 2014-07-29 | Joy Mm Delaware, Inc. | Drive mechanism for a longwall mining machine |
-
1940
- 1940-10-14 US US361030A patent/US2283461A/en not_active Expired - Lifetime
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2650811A (en) * | 1947-06-17 | 1953-09-01 | Joy Mfg Co | Tilting arrangement for shortwall coal cutting machines |
US2678204A (en) * | 1950-07-17 | 1954-05-11 | Joy Mfg Co | Tiltable mounting structure for coal cutting machines |
US8789892B2 (en) | 2010-10-29 | 2014-07-29 | Joy Mm Delaware, Inc. | Drive mechanism for a longwall mining machine |
US9309763B2 (en) | 2010-10-29 | 2016-04-12 | Joy Mm Delaware, Inc. | Drive mechanism for a longwall mining machine |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2595398A (en) | Coal cutting and loading machine | |
US2360282A (en) | Loading machine | |
US2283461A (en) | Kerf-cutting machine | |
US2323493A (en) | Kerf-cutting machine | |
US2007109A (en) | Loading machine | |
US2024458A (en) | Material gathering and loading machine | |
US2320653A (en) | Mining apparatus | |
US2384083A (en) | Kerf-cutting machine | |
US2326857A (en) | Self-loading device for shaker conveyers | |
US2225666A (en) | Mining machine | |
US2332546A (en) | Mounted kerf-cutting machine | |
US2999554A (en) | Machine propelling mechanism | |
US2100336A (en) | Mining apparatus | |
US2208269A (en) | Conveyer | |
US2609910A (en) | Loading machine | |
US2206598A (en) | Mining machine transport means | |
US2307966A (en) | Mining machine | |
US2253626A (en) | Kerf-cutting machine | |
US1183102A (en) | Mining-machine moving and holding device. | |
US2559711A (en) | Mining machine | |
US3431660A (en) | Earth scraper with sliding vertical elevator guide means | |
US2010449A (en) | Coal mining machine | |
US2261161A (en) | Mining apparatus | |
US2612362A (en) | Kerf-cutting machine | |
US2648444A (en) | Timber setting machine |